1. Field of the Invention
The present invention relates to test ports and, more particularly, to test ports for use with conventional gasoline/diesel fuel dispensers.
2. Description of Related Prior Art
From time to time the pressurized line system found in conventional petroleum fueling sites, such as gasoline/diesel fuel pumps/dispensers. These fueling sites include a mechanical line leak detector that must be tested to ensure proper functioning. To test these detectors, access to the pressurized line system is necessary. Additionally, such access is required for general inspections and troubleshooting to determine the cause of a fault.
For safety reasons, every dispenser includes an impact/shear valve located slightly below grade beneath each fuel dispenser. The primary function of this valve is to stop the flow of pressurized fuel if the dispenser is struck or dislodged due to accident or otherwise. Because these valves are commonly made of soft cast metal any seam may split and any threads are easily stripped creating a need to replace these valves.
It is not unusual for a technician to obtain fluid communication with the pressurized line system by removing a plug from the impact/shear valve and inserting therein a test probe. By removing such a plug to gain access to the threaded opening in the impact/shear valve, fuel will be discharged as a function of the line pressure. This creates an obvious mechanical hazard for the technician, a fire hazard for the immediate environment, evaporation of the fuel degrades the air quality and the spilled fuel potentially creates ground or ground water pollution.
To reduce the line pressure by removing the plug requires good judgment and patience, if the plug is turned too many times to vent the line pressure, the plug may be sufficiently dislodged to become a projectile and potentially injuring a technician or surrounding personnel or objects. While many pressurized line systems have a high bulk modulus (rapid change of pressure for a relatively small amount of fuel), a significant number of pressurized lines have flexible lines, many flexible connectors, trapped vapor, or any combination thereof which may require thirty minutes or more to safely bleed the line to allow safe access to the line system. To avoid the hazards of removing a plug from the impact/shear valve, some technicians have replaced the plug with a quick connect fitting. A hose is attached thereto to drain fuel discharged from the pressurized line system into a container. While this solution avoids an inadvertent spray of fuel, other issues are created.
In an attempt to protect the quick connect valve, a cover is often employed. Nevertheless, the opening of the impact/shear valve to mount the quick connect fitting was always dangerous. Secondarily, the integrity of a quick connect fitting may be damaged during an impact to the gasoline/diesel fuel dispenser. With the integrity of the quick connect fitting compromised, their location provides an unfortunate flow path that defeated the purpose of the impact/shear valve supporting the damaged quick connect fitting. These damaged quick connect fittings have caused destruction of property and loss of life. Therefore, fire and safety personnel have precluded these quick connect fittings from being installed and often have required existing quick connect fittings to be removed. Thus, technicians have had to revert to removing a plug from the impact/shear valve to perform the required tests and the attendant safety hazards continue to exist.